Metal air battery including multi module air supply unit

ABSTRACT

A metal air battery includes a multi module air supply unit having air suction units or air purification units in a parallel arrangement. The metal air battery further includes a battery module including a metal air cell and the air supply unit which supplies the air to the battery module. The air supply unit includes an air suction unit which suctions air and an air purification unit that adsorbs impurities such as moisture and nitrogen from the suctioned air. The air suction unit or the air purification unit may be provided in plural to be in a parallel arrangement to define the multi module air supply unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2016-0162300, filed on Nov. 30, 2016, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a metal air battery, and moreparticularly, to a metal air battery including a multi module air supplyunit with two or more air suction units or air purification units in aparallel arrangement.

2. Description of the Related Art

A metal air battery includes a plurality of metal air cells. Each of themetal air cells includes an anode capable of intercalating anddeintercalating ions and a cathode using oxygen from air as an activematerial. A reduction/oxidation of oxygen introduced from the outsidethe metal air battery occurs at the cathode, and an oxidation/reductionof a metal occurs at the anode. The metal air battery changes thechemical energy generated when the oxidation/reduction reaction occursinto electrical energy and outputs the electrical energy. For example,the metal air battery absorbs oxygen during discharging and emits oxygenduring charging. As described above, since the metal air battery usesoxygen from the air, an energy density of the battery may significantlyimprove. For example, the metal air battery may have an energy densityseveral times higher than an energy density of a conventional lithiumion battery.

In addition, since the metal air battery has a relatively lowprobability of ignition caused by an abnormally high temperature, themetal air battery has relatively high stability. Also, since the metalair battery is operated only by absorption and emission of oxygenwithout using a heavy metal, there is a relatively low probability ofthe metal air battery contaminating the environment. Due to such variousadvantages, much research into the metal air battery has been performed.

SUMMARY

According to an embodiment, a metal air battery includes a batterymodule which generates electricity, the battery module including a metalair cell which uses oxygen from air as a cathode active material togenerate the electricity; and an air supply unit which is connected tothe battery module and supplies the air to the battery module. The airsupply unit includes an air suction unit which suctions air fromoutside, and an air purification unit connected to the air suction unitto receive suctioned air therefrom and remove impurities from thesuctioned air. The air suction unit includes a plurality of air-handlingmodules connected in a parallel arrangement with each other to define amulti module structure of the air suction unit.

In an embodiment, the air suction unit further includes one air tankwhich stores the suctioned air; and as the plurality of air-handlingmodules of the air suction unit, a plurality of compressors connected ina parallel arrangement with each other, each compressor being connectedto the one single air tank to suction air from the outside and providethe suctioned air to the one single air tank.

In an embodiment, the air suction unit further includes a plurality ofair tanks each of which stores air; as the plurality of air-handlingmodules of the air suction unit, a plurality of compressors connected ina parallel arrangement with each other, the compressors beingrespectively connected to the plurality of air tanks to suction air fromthe outside and provide the suctioned air to a corresponding air tank;and a plurality of valves respectively connected to the plurality of airtanks to control an amount of air output from the plurality of airtanks.

In an embodiment, the metal air battery further includes a sensor unitincluding a plurality of pressure meters respectively connected to theplurality of air tanks of the air suction unit to measure an internalpressure in a corresponding air tank.

In an embodiment, the metal air battery further includes a controllerconnected to the sensor unit and to the air supply unit to receiveinternal pressure information of the plurality of air tanks of the airsuction unit provided from the plurality of pressure meters of thesensor unit. The controller controls the plurality of valves of the airsuction unit based on the internal pressure information to control theamount of air output from the plurality of air tanks.

In an embodiment, from among the plurality of air tanks of the airsupply unit, the controller further controls the amount of air outputfrom an air tank having the highest internal pressure to be a maximumamount, and controls the amount of air output from an air tank havingthe lowest internal pressure to be a minimum amount.

In an embodiment, from among the plurality of air tanks of the airsupply unit, the controller further ceases the amount of air output froman air tank having an internal pressure less than a reference pressureby closing a valve connected to such air tank.

In an embodiment, from among the plurality of air tanks of the airsupply unit, the controller further opens a valve of an air tank havingthe highest internal pressure and closes valves of remaining air tanks.

In an embodiment, the controller further opens the valve of the air tankhaving the highest internal pressure and closes the valves of remainingair tanks according to change of the internal pressure of the pluralityof air tanks.

In an embodiment, from among the plurality of air tanks respectivelyconnected to the plurality of compressors of the air supply unit, thecontroller operates a compressor connected to an air tank having aninternal pressure less than a reference pressure until such air tankreaches a maximum pressure and ceases operation of a compressorconnected to an air tank having an internal pressure which has reachedthe maximum pressure.

In an embodiment, air-handling capacities of the plurality ofcompressors are same.

In an embodiment, air-handling capacities of the plurality ofcompressors are different from each other.

In an embodiment, capacities of the plurality of air tanks are differentfrom each other.

In an embodiment, the air purification unit includes a plurality ofair-handling modules connected in a parallel arrangement with each otherto define a multi module structure of the air purification unit.

In an embodiment, the air purification unit includes as the plurality ofair-handling modules, a plurality of air purifiers connected in aparallel arrangement with each other, each air purifier receiving thesuctioned air from the air suction unit to separate the impurities fromthe suctioned air and output a remainder of the suctioned air to thebattery module.

In an embodiment, the plurality of air purifiers removes moisture andnitrogen from air by adsorption-desorption or removes moisture andnitrogen by an impurity separator.

In an embodiment, each of the air purifiers includes a first adsorptionunit and a second adsorption unit each of which separates the impuritiesfrom the suctioned air. The first adsorption unit includes a firstadsorbent which adsorbs impurities and a first regeneration unit whichregenerates the first adsorbent, and the second adsorption unit includesa second adsorbent which adsorbs impurities and a second regenerationunit which regenerates the second adsorbent.

In an embodiment, each of the plurality of air purifiers operatesaccording to a pressure swing adsorption (“PSA”) method, a thermal swingadsorption (“TSA”) method, a pressure thermal swing adsorption (“PTSA”)method, or a vacuum swing adsorption (“VSA”) method.

In an embodiment, each of the plurality of air purifiers includes anoxygen separator including a separation member, such oxygen separatorseparating nitrogen from the suctioned air, and a pump connected to theoxygen separator to output the suctioned air having the nitrogen removedtherefrom to the battery module.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other features will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a block diagram schematically illustrating an exemplaryembodiment of a structure of a metal air battery according to theinvention;

FIG. 2 is a block diagram schematically illustrating an exemplaryembodiment of a structure of an air supply unit of the metal air batteryshown in FIG. 1;

FIG. 3 is a schematic view of an exemplary embodiment of a structure ofan air suction unit having a multi module structure according to theinvention;

FIG. 4 is a schematic view of another exemplary embodiment of astructure of an air suction unit having a multi module structureaccording to the invention;

FIG. 5 is a schematic view of still another exemplary embodiment ofstructure of an air suction unit having a multi module structureaccording to the invention;

FIG. 6 is a schematic view of an exemplary embodiment of a structure ofan air purification unit having a multi module structure according tothe invention;

FIG. 7 is a schematic diagram of an exemplary embodiment of a structureof an air purification module of the air purification unit shown in FIG.6;

FIG. 8 is a schematic diagram of another exemplary embodiment of astructure of an air purification module of the air purification unitshown in FIG. 6; and

FIGS. 9 and 10 are graphs showing an effect exhibited when an airpurification unit has a multi module structure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of a metal air battery including amulti module air supply unit will be described in detail with referenceto the accompanying drawings.

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which various embodiments areshown. This invention may, however, be embodied in many different forms,and should not be construed as limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the scope of theinvention to those skilled in the art. Like reference numerals refer tolike elements throughout. In the drawings, the dimensions of elementsare exaggerated for clarity of the invention. The following embodimentsare merely examples, and various modifications may be made thereto.

It will be understood that when an element is referred to as beingrelated to another element such as being “on,” “connected to” or“coupled to” another element, it may be directly on, connected orcoupled to the other element or intervening elements may be present. Incontrast, when an element is referred to as being related to anotherelements such as being “directly on” another element, there are nointervening elements present. As two elements are described as being“connected,” “coupled to,” etc. to each other, such connection mayindicate a physical, electrical and/or fluid connection.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “At least one” is not to be construed as limiting “a” or“an.” “Or” means “and/or.” As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.It will be further understood that the terms “comprises” and/or“comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

FIG. 1 is a block diagram schematically illustrating an exemplaryembodiment of a metal air battery 100 according to the invention.Referring to FIG. 1, the metal air battery 100 may include a batterymodule 110 which generates electricity and includes at least one metalair cell 111 that uses oxygen from air as a cathode active material; andan air supply unit 130 that supplies the air to the battery module.Also, the metal air battery 100 may further include a sensor unit 120including a sensor (not shown) provided in plurality for an operation ofthe battery module 110 and the air supply unit 130; and a controller 140that controls an operation of the air supply unit 130. The controller140 may control an operation of the sensor unit 120. In an exemplaryembodiment, for example, the sensor unit 120 may include a pressuremeter (not shown) that measures a pressure in an air tank of the airsupply unit 130; and an oxygen sensor that measures an oxygenconcentration of air supplied from the air supply unit 130 to thebattery module 110. The battery module 110, sensor unit 120, air supplyunit 130 and controller 140 may be connected to each other, such as inmechanical, electrical and/or fluid communication with each other viaports and/or outlets.

The battery module 110 may include at least one metal air cell 111 usingoxygen from air as a cathode active material. Each metal air cell 111 inthe battery module 110 may generate electricity according to anoxidation of a metal and a reduction of oxygen. In an exemplaryembodiment, for example, when a metal is lithium (Li), the metal aircell 111 may generate electricity through a reaction in which lithium(Li) reacts with oxygen to generate lithium oxide (Li₂O₂) duringdischarging. In the battery module 110 and/or the metal air cell 111,lithium (Li) may be reduced from lithium oxide and oxygen may begenerated during charging.

Besides lithium (Li), various metals may also be used, and a reactionprincipal thereof may be substantially the same as lithium (Li). In anexemplary embodiment, for example, the battery module 110 may include atleast one selected from sodium (Na) air cells, zinc (Zn) air cells,potassium (Ka) air cells, calcium (Ca) air cells, magnesium (Mg) aircells, iron (Fe) air cells, aluminum (Al) air cells, and alloy air cellsincluding two or more of Na, Zn, Ka, Ca, Mg, and Fe.

As described above, since the battery module 110 uses oxygen during adischarging process, oxygen should be continuously supplied to thebattery module 110. To supply oxygen to the battery module, the airsupply unit 130 suctions air from the atmosphere (i.e., external to themetal air battery 100 or components thereof) and supplies the suctionedair to the battery module 110.

FIG. 2 is a block diagram that schematically illustrates an exemplaryembodiment of a structure of the air supply unit 130 of the metal airbattery 100 shown in FIG. 1. Referring to FIG. 2, the air supply unit130 may include an air suction unit 131 that is configured to suctionair from outside thereof; and an air purification unit 136 for removingimpurities from the suctioned air of the air suction unit 131. The airsuction unit 131, the air purification unit 136 and the controller 140may be connected to each other, such as in mechanical, electrical and/orfluid communication with each other via ports and/or outlets.

The air suction unit 131 may be configured to control an amount of thesuctioned air thereto according to or under control of the controller140. Also, the air purification unit 136 may remove impurities from thesuctioned air under control of the controller 140 to control an oxygenconcentration in the air supplied to the battery module 110 to anoptimum value. In an exemplary embodiment, for example, the airpurification unit 136 may remove moisture and nitrogen from thesuctioned air. When the air includes moisture, a lithium hydroxide maybe produced during the discharging process of the metal air cell 111,and thus an energy density and lifespan of the metal air battery 100 maydecrease. Also, an oxygen concentration in the air supplied to thebattery module 110 may increase by removing nitrogen from the suctionedair. In an exemplary embodiment, for example, the air purification unit136 may output moisture and nitrogen via a first outlet port 136 a andmay supply dry air with an increased oxygen concentration to the batterymodule 110 via a second outlet port 136 b.

As a volume and a weight of the metal air battery 100 increase, anenergy density of the metal air battery 100 may decrease. Therefore,when the metal air battery 100 is miniaturized while maintaining orimproving overall performance of the metal air battery 100, an energydensity of the metal air battery 100 may increase. According to one ormore embodiment, when the metal air battery 100 has a multi modulestructure in which at least one of the air suction unit 131 and the airpurification unit 136 of the air supply unit 130 is manufactured toinclude a multi module structure having a plurality of modules in aparallel arrangement, performance of the air suction unit 131 and/or theair purification unit 136 may be maintained or improved. At the sametime, with the multi module structure described above, an energy densityof the metal air battery 100 may increase by decreasing a volume and aweight of the air suction unit 131 and/or the air purification unit 136.

FIG. 3 is schematic view of an exemplary embodiment of a structure ofthe air suction unit 131 having a multi module structure according tothe invention. Referring to FIG. 3, the air suction unit 131 may includean air tank 132 that stores air; a plurality of compressors 133 a, 133b, 133 c and 133 d that are connected to the same air tank 132; and anoutput valve 135 that controls an amount of air output from the air tank132 according to control of the controller 140. The air tank 132 may becommonly connected to each of the plurality of compressors 133 a, 133 b,133 c and 133 d. Although FIG. 3 shows that four compressors 133 a, 133b, 133 c and 133 d are connected to the same air tank 132 as an example,embodiments are not limited thereto. As shown in FIG. 3, the pluralityof compressors 133 a, 133 b, 133 c and 133 d may be in a parallelarrangement. That is, each of the plurality of compressors 133 a, 133 b,133 c and 133 d may suction air from the outside thereof or from outsidethe metal air battery 100 and supply the air to the air tank 132. Asingle air-handling module may include a compressor, the single one airtank and the single one output value which are connected to each otherin series, but the invention is not limited thereto. In an exemplaryembodiment, a single air-handling module may include a compressor amonga plurality thereof connected to each other in a parallel arrangement.

In an exemplary embodiment of the air suction unit 131 shown in FIG. 3,the sensor unit 120 may include a pressure meter (not shown) which isdisposed in and/or connected to components of the air suction unit 131.The pressure meter is configured to measure an internal pressure in theair tank 132.

When outside air is suctioned by using the plurality of compressors 133a, 133 b, 133 c and 133 d as described above for a total amount ofsuctioned air, an overall volume and a weight of the air suction unit131 may decrease as compared to a structure where one single compressorsuctions air in the same total amount as that air suctioned by theplurality of compressors 133 a, 133 b, 133 c and 133 d.

FIG. 4 is a schematic view that shows another exemplary embodiment of astructure of the air suction unit 131 having a multi module structureaccording to the invention. Referring to FIG. 4, the air suction unit131 may include a plurality of air tanks 132 a, 132 b, 132 c, and 132 dthat store air provided thereto; a plurality of compressors 133 a, 133b, 133 c and 133 d that retrieve air from outside thereof or fromoutside the metal air battery 100 and are respectively connected to theplurality of air tanks 132 a, 132 b, 132 c and 132 d; and a plurality ofoutput valves 135 a, 135 b, 135 c and 135 d that respectively control anamount of air output from the plurality of air tanks 132 a, 132 b, 132 cand 132 d according to control of the controller 140. The plurality ofoutput valves 135 a, 135 b, 135 c and 135 d may then be commonlyconnected to another component such as the air purification unit 136 viaa common channel. Different shadings in the air tanks 132 a, 132 b, 132c, and 132 d of FIG. 4 illustrate examples of amount of air stored inthe air tanks 132 a, 132 b, 132 c, and 132 d. A single air-handlingmodule may include a compressor, an air tank and an output value whichare connected to each other in series but the invention is not limitedthereto. In an exemplary embodiment, a single air-handling module mayinclude a compressor, an air tank and/or an output valve among aplurality thereof connected to each other in a parallel arrangement.

The sensor unit 120 may include a plurality of pressure meters 121 a,121 b, 121 c and 121 d. The plurality of pressure meters 121 a, 121 b,121 c and 121 d may be disposed in and/or connected to components of theair suction unit 131. Each of the pressure meters 121 a, 121 b, 121 cand 121 d is configured to measure an internal pressure in acorresponding air tank of the plurality of air tanks 132 a, 132 b, 132 cand 132 d. Although FIG. 4 shows that the air suction unit 131 includesfour air tanks 132 a, 132 b, 132 c and 132 d as an example, butembodiments are not limited thereto. Also, although FIG. 4 shows thatone of the compressors 133 a, 133 b, 133 c and 133 d is connected to oneof the air tanks 132 a, 132 b, 132 c and 132 d, a plurality ofcompressors may be commonly connected to a single one of the air tanksamong air tanks 132 a, 132 b, 132 c and 132 d as in FIG. 3. As shown inFIG. 4, the plurality of air tanks 132 a, 132 b, 132 c and 132 d may bein a parallel arrangement. That is, air output from the plurality of airtanks 132 a, 132 b, 132 c and 132 d may be supplied to the airpurification unit 136 through one air channel.

In the structure shown in FIG. 4, the controller 140 connected to theair supply unit 130 may receive internal pressure information of theplurality of air tanks 132 a, 132 b, 132 c and 132 d provided from theplurality of pressure meters 121 a, 121 b, 121 c and 121 d, may controlthe plurality of output valves 135 a, 135 b, 135 c and 135 d based onthe pressure information, and thus may control an amount of air outputfrom the plurality of air tanks 132 a, 132 b, 132 c and 132 d. In anexemplary embodiment, for example, the controller 140 may control an airamount output from an air tank having the highest internal pressureamong the plurality of air tanks 132 a, 132 b, 132 c and 132 d to be amaximum amount and may control an air amount output from an air tankhaving the lowest internal pressure among the plurality of air tanks 132a, 132 b, 132 c and 132 d to be a minimum amount. Also, the controller140 may close an output valve of an air tank having an internal pressureless than a reference pressure among the plurality of air tanks 132 a,132 b, 132 c and 132 d to stop discharging air and put the air tank inan idle state until the internal pressure increases to a pressure higherthan the reference pressure. Also, the controller 140 may open an outputvalve of the air tank having the highest internal pressure among theplurality of air tanks 132 a, 132 b, 132 c and 132 d and may closeoutput valves of the other air tanks.

Thereafter, the controller 140 may select an air tank that outputs airin real-time according to a change in an internal pressure of theplurality of air tanks 132 a, 132 b, 132 c and 132 d. Also, thecontroller 140 may only open output valves of at least two air tankshaving the highest internal pressures among the plurality of air tanks132 a, 132 b, 132 c and 132 d and may close output valves of the otherair tanks. That is, the controller 140 connected to the air supply unit130 may open and close the output valves of the air support unit 130 invarious combinations to control an amount of air output from theplurality of air tanks 132 a, 132 b, 132 c and 132 d.

Also, the controller 140 may control operation of the plurality ofcompressors 133 a, 133 b, 133 c and 133 d according to internal pressureinformation of the plurality of air tanks 132 a, 132 b, 132 c and 132 dfrom the sensor unit 120. In an exemplary embodiment, for example, thecontroller 140 may drive the compressors connected to the air tankshaving internal pressures lower than the reference pressure among theplurality of air tanks 132 a, 132 b, 132 c, and 132 d to be a maximumpressure and may stop operation of the compressors connected to the airtanks having internal pressures that reached the maximum pressure or maydrive the operation of such air tank at a minimum (e.g., for a minimumtime, under minimum power, etc.).

According to one or more embodiment shown in FIG. 4, the air suctionunit 131 may actively respond with respect to an internal pressurestatus of the plurality of air tanks 132 a, 132 b, 132 c and 132 d, andthus, may continuously supply a constant amount or a minimum amount ofair to the air purification unit 136 without ceasing to supply air.Also, an overall size of the air suction unit 131 may decrease comparedto when only a single one air tank and a single one compressor are used.

Although FIG. 4 shows that all sizes of the plurality of compressors 133a, 133 b, 133 c and 133 d are the same and loads (e.g., air-handlingcapacity) of the plurality of compressors 133 a, 133 b, 133 c and 133 dare the same, sizes of the plurality of compressors 133 a, 133 b, 133 c,and 133 d may be different from each other and loads of the plurality ofcompressors compressors 133 a, 133 b, 133 c, and 133 d may be differentfrom each other. In the drawings, sizes of the compressors relative toeach other are used to indicate relative air-handling capacitiestherebetween.

FIG. 5 is a schematic view of still another exemplary embodiment of astructure of the air suction unit 131 having a multi module structureaccording to the invention. Referring to FIG. 5, the air suction unit131 may include a plurality of air tanks 132 a, 132 b and 132 c; aplurality of compressors 133 a, 133 b and 133 c having different sizesfrom each other and respectively connected to the plurality of air tanks132 a, 132 b and 132 c; and a plurality of output valves 135 a, 135 band 135 c that respectively control an amount of air output from the airtanks 132 a, 132 b and 132 c according to control of the controller 140.Also the sensor unit 120 may include a plurality of pressure meters 121a, 121 b and 121 c, each being configured to measure an internalpressure in a corresponding air tank of the plurality of air tanks 132a, 132 b and 132 c.

Although FIG. 5 shows that a size of one compressor 133 a is the largestrelative to the remaining compressors, and two other compressors 133 band 133 c with smaller sizes than that of the compressor 133 a have thesame sizes as each other, embodiments are not limited thereto. In anexemplary embodiment, for example, all sizes of the plurality ofcompressors 133 a, 133 b and 133 c may be different from each other.Also, there may be two compressors having the largest size among theplurality of compressors 133 a, 133 b and 133 c. Also, FIG. 5 shows thatthe plurality of air tanks 132 a, 132 b and 132 c have the same sizes,but when sizes of the plurality of compressors 133 a, 133 b and 133 care different from each other, capacities (or volumes) of the air tanks132 a, 132 b and 132 c respectively connected to the compressors 133 a,133 b and 133 c and performance of the output valves 135 a, 135 b and135 c may selected differently depending on operation of the air suctionunit 130.

Referring to the structure of FIG. 5, air is mainly supplied from theair tank 132 a connected to the compressor 133 a having the largest sizeamong the plurality of compressors 133 a, 133 b and 133 c. To reach acertain amount of air, a supplemental amount of air other than the airsupplied from the largest air tank may be respectively filled by usingthe air tanks 132 b and 132 c connected to the compressors 133 b and 133c having the relatively smaller sizes. Also, in consideration of thesizes of the compressors and/or air tanks, the plurality of compressors133 a, 133 b and 133 c may be selectively combined to supply airaccording to change in an amount or air used in the battery module 110.

The air purification unit 136 may be manufactured in a multi modulestructure. FIG. 6 is a schematic view of an exemplary embodiment of astructure of the air purification unit 136 having a multi modulestructure according to the invention. Referring to FIG. 6, the airpurification unit 136 may include a plurality of air purificationmodules 137 a, 137 b, 137 c and 137 d in a parallel arrangement. Also,the air purification unit 136 may further include a plurality of valves138 a, 138 b, 138 c and 138 d that are respectively connected to an airoutlet port of the plurality of air purification modules 137 a, 137 b,137 c and 137 d. Although FIG. 6 shows four air purification modules 137a, 137 b, 137 c and 137 d in a parallel arrangement as an example,embodiments are not limited thereto. Also, although FIG. 6 shows theplurality of air purification modules 137 a, 137 b, 137 c and 137 dhaving the same size as each other for convenience of description, sizesand corresponding capacities of the plurality of air purificationmodules 137 a, 137 b, 137 c and 137 d may be different from each other.A single air-handling module may include an air purification module anda valve which are connected to each other in series but the invention isnot limited thereto. In an exemplary embodiment, a single air-handlingmodule may include an air purification module or a valve among aplurality thereof connected to each other in a parallel arrangement.

Air supplied from the air suction unit 131 is input to the plurality ofair purification modules 137 a, 137 b, 137 c and 137 d of the airpurification unit 136. Then, the air purification modules 137 a, 137 b,137 c and 137 d may operate independent from each other and thus maygenerate dry air, from which moisture and nitrogen are removed. Suchgenerated dry air has an increased oxygen concentration and istransmitted through the valves 138 a, 138 b, 138 c and 138 drespectively connected to the air purification modules 137 a, 137 b, 137c and 137 d. Also, each of the air purification modules 137 a, 137 b,137 c and 137 d may output the removed moisture and nitrogen to theoutside of the metal air battery 100 such as through a separate outletport (refer to 136 a of FIG. 2). The dry air having an increased oxygenconcentration output from the plurality of air purification modules 137a, 137 b, 137 c and 137 d may be supplied to the battery module 110through one common air channel (refer to 136 b of FIG. 2).

In an exemplary embodiment, for example, each of the air purificationmodules 137 a, 137 b, 137 c and 137 d may independently remove moistureand nitrogen from air supplied thereto by adsorption and desorption, ormay remove moisture and nitrogen from air supplied thereto by separationmembrane.

FIG. 7 is a block diagram that schematically illustrates an exemplaryembodiment of a structure of one single air purification module 137 ofthe air purification unit 136 shown in FIG. 6. The air purificationmodule 137 shown in FIG. 7 is configured to filter moisture and nitrogenby adsorption and desorption. Referring to FIG. 7, the air purificationmodule 137 may include a first adsorption unit 31 and a secondadsorption unit 32 in a parallel arrangement with each other. The firstadsorption unit 31 may include a first adsorbent 31 a and a firstregeneration unit 31 b, and the second adsorption unit 32 may include asecond adsorbent 32 a and a second regeneration unit 32 b.

The first adsorbent 31 a and the second adsorbent 32 a may function toadsorb impurities such as nitrogen from air. In an exemplary embodiment,for example, the first adsorbent 31 a and the second adsorbent 32 a mayinclude one selected from zeolite LiX, alumina, a metal-organicframework (“MOF”), a zeolite imidazolate framework (“ZIF”), andcombinations including two or more thereof. The MOF may include a metalion or a metal cluster which is coordinated to an organic molecule andmay define a crystalline compound forming a primary, secondary ortertiary porous structure. In addition, the ZIF may mean a nanoporouscompound including a tetrahedral cluster of MN₄ that is linked by animidazolate ligand (where M is a metal).

The first regeneration unit 31 b and the second regeneration unit 32 bmay function to regenerate the saturated first adsorbent 31 a and thesaturated second adsorbent 32 a, respectively, so that the saturatedfirst adsorbent 31 a and the saturated second adsorbent 32 a may againadsorb impurities from air. In order to regenerate the saturated firstadsorbent 31 a and the saturated second adsorbent 32 a, the firstregeneration unit 31 b and the second regeneration unit 32 b may beconfigured to adjust an inner pressure and/or temperature of the firstadsorption unit 31 and an inner pressure or temperature of the secondadsorption unit 32, respectively.

The air purification module 137 having the aforementioned structure mayoperate, for example, in a pressure swing adsorption (“PSA”) method. Inan exemplary embodiment, for example, impurities such as moisture andnitrogen may be adsorbed to the first adsorbent 31 a by increasing theinner pressure of the first adsorption unit 31 to operate the firstadsorption unit 31. The remaining air from which the impurities havebeen removed and having an increased oxygen concentration may be outputfrom the first adsorption unit 31 to a first outlet port 113 a.Meanwhile, the moisture and nitrogen adsorbed to the second adsorbent 32a may be desorbed from the second adsorbent 32 a by decreasing the innerpressure of the second adsorption unit 32, and the desorbed moisture andnitrogen may be discharged from the second adsorption unit 32 to asecond outlet port 113 b.

When the first adsorbent 31 a is saturated, the inner pressure of thefirst adsorption unit 31 may be decreased, and the inner pressure of thesecond adsorption unit 32 may be increased. In this case, a desorbingoperation may be performed in the first adsorption unit 31, and anadsorbing operation may be performed in the second adsorption unit 32.In such a manner, the first adsorption unit 31 and the second adsorptionunit 32 may alternately operate. At this time, the oxygen concentrationin the air supplied to the battery module 110 may be adjusted bycontrolling the inner pressure of each of the first adsorption unit 31and the second adsorption unit 32.

However, an operation manner of the air purification module 137 is notnecessarily limited to the PSA method. For example, in addition to thePSA method, the air purification module 137 may be configured to operatein a thermal swing adsorption (“TSA”) method, a pressure thermal swingadsorption (“PTSA”) method, a vacuum swing adsorption (“VSA”) method, ortwo or more thereof. The PSA method means a technology of primarilyadsorbing or capturing a specific gas to the first adsorbent 31 a andthe second adsorbent 32 a at a high partial pressure, and desorbing ordischarging the specific gas when the partial pressure is decreased. Inaddition, the TSA method means a technology of primarily adsorbing orcapturing a specific gas to the first and second adsorbents 31 a and 32a at room temperature, and desorbing or discharging the specific gaswhen the temperature is increased. The PTSA method means a technology inwhich the PSA method and the TSA method are combined. Finally, the VSAmethod means a technology of primarily adsorbing or capturing a specificgas to the first and second adsorbents 31 a and 32 a at about anatmospheric pressure, and desorbing or discharging the specific gasunder a vacuum.

FIG. 8 is a schematic block diagram of another exemplary embodiment of astructure of one single air purification module 137 of the airpurification unit 136 illustrated in FIG. 6, according to the invention.The air purification module 137 illustrated in FIG. 8 may be configuredto filter oxygen via a separation membrane method. Referring to FIG. 8,the air purification module 137 may include a pump 36 and an oxygenseparation module 34 which is configured to separate nitrogen and oxygenin air supplied thereto. The pump 36 may be connected to the oxygenseparation module 34. A membrane 35 may be disposed within the oxygenseparation module 34 to selectively separate oxygen. Although FIG. 8shows one membrane 35 for convenience, a plurality of membranes 35 maybe disposed in a multi-layered structure. In an exemplary embodiment,for example, the membrane 35 may include a BSCF oxide(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)).

The air suctioned by the air suction unit 131 may be supplied to theoxygen separation module 34, and the membrane 35 in the oxygenseparation module 34 may filter oxygen from the air. A gas remainingafter oxygen is separated in the oxygen separation module 34 may bedischarged to the outside through the second outlet port 113 c. The pump36 may supply oxygen to the battery module 110 through the first outletport 113 d by emitting oxygen from the oxygen separation module 34.

FIGS. 9 and 10 are graphs that show effects when the air purificationunit 136 has a multi module structure. First, FIG. 9 shows arelationship between an oxygen concentration in percent (%) in airoutput from the air purification unit 136 and an air flow amount inliters per minute (LPM). In FIG. 9, ‘♦’ indicates the results of acomparative example using one adsorption module, ‘*’ indicates theresults of an example using one adsorption module from a multi modulestructure which individually has a ¼ load (e.g., capacity) of theadsorption module used in the comparative example. Referring to thegraph of FIG. 9, when an oxygen concentration in air supplied to abattery module (refer to 110 in FIG. 1) is 40%, the comparative examplemay supply air at about 110 LPM. On the other hand, despite using oneadsorption module from a multi module structure which individually has a¼ capacity of the adsorption module used in the comparative example, theexample may supply air at about 70 LPM when an oxygen concentration inair supplied to the battery module is 40%. Therefore, when two or moreadsorption modules having a ¼ capacity of the adsorption module used inthe comparative example are used in a parallel arrangement to form amulti module structure, performance of the overall air purification unit136 may improve compared to that of the single one air purification unitof the comparative example.

Referring to the arbitrary units in the graph of FIG. 10, when the totalcapacities of the adsorption modules of the comparative example and theexample are the same, a weight of the air purification unit 136 of oneor more exemplary embodiment may decrease about 60% compared to that ofthe comparative example. A flow rate of one or more exemplary embodimentof the air purification unit 136 may increase to be about 2.5 timeshigher than that of the comparative example. Therefore, when the airpurification unit 136 is manufactured to have a multi module structureaccording to one or more embodiment of the invention, a weight and avolume of the metal air battery 100 may decrease, and thus an energydensity of the metal air battery 100 may increase.

Although one or more exemplary embodiment of the metal air batteryincluding a multi module air supply unit has been described above byreferring to the accompanied drawings, it should be understood thatembodiments described herein should be considered in a descriptive senseonly and not for purposes of limitation. Descriptions of features withineach embodiment should typically be considered as available for othersimilar features in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A metal air battery comprising: a battery modulewhich generates electricity, the battery module comprising a metal aircell which uses oxygen from air as a cathode active material to generatethe electricity; and an air supply unit which is connected to thebattery module and supplies the air to the battery module, wherein theair supply unit comprises: an air suction unit which suctions air fromoutside, and an air purification unit connected to the air suction unitto receive suctioned air therefrom and remove impurities from thesuctioned air, and the air suction unit comprises a plurality ofair-handling modules connected in a parallel arrangement with each otherto define a multi module structure of the air suction unit.
 2. The metalair battery of claim 1, wherein the air suction unit further comprises:one single air tank which stores the suctioned air; and as the pluralityof air-handling modules of the air suction unit, a plurality ofcompressors connected in a parallel arrangement with each other, eachcompressor being connected to the one single air tank to suction airfrom the outside and provide the suctioned air to the one single airtank.
 3. The metal air battery of claim 1, wherein the air suction unitfurther comprises: a plurality of air tanks each of which stores air; asthe plurality of air-handling modules of the air suction unit, aplurality of compressors connected in a parallel arrangement with eachother, the compressors being respectively connected to the plurality ofair tanks to suction air from the outside and provide the suctioned airto a corresponding air tank; and a plurality of valves respectivelyconnected to the plurality of air tanks to control an amount of airoutput from the plurality of air tanks.
 4. The metal air battery ofclaim 3, further comprising: a sensor unit comprising a plurality ofpressure meters respectively connected to the plurality of air tanks ofthe air suction unit to measure an internal pressure in a correspondingair tank.
 5. The metal air battery of claim 4, further comprising: acontroller connected to the sensor unit and to the air supply unit toreceive internal pressure information of the plurality of air tanks ofthe air suction unit provided from the plurality of pressure meters ofthe sensor unit, wherein such controller controls the plurality ofvalves of the air suction unit based on the internal pressureinformation to control the amount of air output from the plurality ofair tanks.
 6. The metal air battery of claim 5, wherein from among theplurality of air tanks of the air supply unit, the controller furthercontrols the amount of air output from an air tank having the highestinternal pressure to be a maximum amount, and controls the amount of airoutput from an air tank having the lowest internal pressure to be aminimum amount.
 7. The metal air battery of claim 5, wherein from amongthe plurality of air tanks of the air supply unit, the controllerfurther ceases the amount of air output from an air tank having aninternal pressure less than a reference pressure by closing a valveconnected to such air tank.
 8. The metal air battery of claim 5, whereinfrom among the plurality of air tanks of the air supply unit, thecontroller further opens a valve of an air tank having the highestinternal pressure and closes valves of remaining air tanks.
 9. The metalair battery of claim 8, wherein the controller further opens the valveof the air tank having the highest internal pressure and closes thevalves of remaining air tanks according to change of the internalpressure of the plurality of air tanks.
 10. The metal air battery ofclaim 5, wherein from among the plurality of air tanks respectivelyconnected to the plurality of compressors of the air supply unit, thecontroller operates a compressor connected to an air tank having aninternal pressure less than a reference pressure until such air tankreaches a maximum pressure and ceases operation of a compressorconnected to an air tank having an internal pressure which has reachedthe maximum pressure.
 11. The metal air battery of claim 3, whereinair-handling capacities of the plurality of compressors are same. 12.The metal air battery of claim 3, wherein air-handling capacities of theplurality of compressors are different from each other.
 13. The metalair battery of claim 3, wherein capacities of the plurality of air tanksare different from each other.
 14. The metal air battery of claim 1,wherein the air purification unit comprises a plurality of air-handlingmodules connected in a parallel arrangement with each other to define amulti module structure of the air purification unit.
 15. The metal airbattery of claim 14, wherein the air purification unit comprises as theplurality of air-handling modules, a plurality of air purifiersconnected in a parallel arrangement with each other, each air purifierreceiving the suctioned air from the air suction unit to separate theimpurities from the suctioned air and output a remainder of thesuctioned air to the battery module.
 16. The metal air battery of claim15, wherein the plurality of air purifiers removes moisture and nitrogenfrom air by adsorption-desorption or removes moisture and nitrogen fromair by an impurity separator.
 17. The metal air battery of claim 15,wherein for the adsorption-desorption, each of the air purifierscomprises a first adsorption unit and a second adsorption unit each ofwhich separates the impurities from the suctioned air, the firstadsorption unit comprises a first adsorbent which adsorb impurities anda first regeneration unit which regenerates the first adsorbent, and thesecond adsorption unit comprises a second adsorbent which adsorbs theimpurities and a second regeneration unit which regenerates the secondadsorbent.
 18. The metal air battery of claim 17, wherein each of theplurality of air purifiers operates according to a pressure swingadsorption method, a thermal swing adsorption method, a pressure thermalswing adsorption method or a vacuum swing adsorption method.
 19. Themetal air battery of claim 15, wherein each of the plurality of airpurifiers comprises: an oxygen separator including a separation member,wherein such oxygen separator separates nitrogen from the suctioned air,and a pump connected to the oxygen separator to output the suctioned airhaving the nitrogen removed therefrom to the battery module.